Antagonistic interactions between garden yeasts and microfungal garden pathogens of leaf-cutting ants

We investigate the diversity of yeasts isolated in gardens of the leafcutter ant Atta texana. Repeated sampling of gardens from four nests over a 1-year time period showed that gardens contain a diverse assemblage of yeasts. The yeast community in gardens consisted mostly of yeasts associated with plants or soil, but community composition changed between sampling periods. In order to understand the potential disease-suppressing roles of the garden yeasts, we screened isolates for antagonistic effects against known microfungal garden contaminants. In vitro assays revealed that yeasts inhibited the mycelial growth of two strains of Escovopsis (a specialized attine garden parasite), Syncephalastrum racemosum (a fungus often growing in gardens of leafcutter lab nests), and the insect pathogen Beauveria bassiana. These garden yeasts add to the growing list of disease-suppressing microbes in attine nests that may contribute synergistically, together with actinomycetes and Burkholderia bacteria, to protect the gardens and the ants against diseases. Additionally, we suggest that garden immunity against problem fungi may therefore derive not only from the presence of disease-suppressing Pseudonocardia actinomycetes, but from an enrichment of multiple disease-suppressing microorganisms in the garden matrix.

Auxin-producing bacteria isolated from the roots of Cattleya walkeriana, an endangered Brazilian orchid, and their role in acclimatization

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estímulo da solubilização de fosfato resultante da co-inoculação de Aspergillus niger e Burkholderia cepacia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Biodegradação de naftaleno, fenantreno e diesel por isolados do gênero Burkholderia da Amazônia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Identification and enzymatic characterization of acid phosphatase from Burkholderia gladioli

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antimicrobial resistance of heterotrophic marine bacteria isolated from seawater and sands of recreational beaches with different organic pollution levels in southeastern Brazil: evidences of resistance dissemination

Antimicrobial resistance of marine heterotrophic bacteria to different antimicrobials agents were evaluated in seawater, dry and wet sands from three marine recreational beaches with different pollution levels. In all studied beaches, the greatest frequencies of resistance were found in relation to penicillin. on Gonzaguinha, the most polluted beach, 72.3% of all isolated strains showed simple resistance, whilst 8.33% had multiple resistance. The values found on Ilha Porchat beach, were 70.8% and 6.9% for simple and multiple resistances, respectively. on GuaraA(0), the less polluted beach, only 35.3% of isolated strains had simple resistance. Multiple resistance was not observed. While samples from Gonzaguinha and Ilha Porchat beach showed isolated strains resistant to seven and six different antimicrobial agents, respectively, samples from GuaraA(0) beach were resistant only to penicillin and erytromicin. The positive correlations obtained between the degree of seawater contamination and frequency and variability of bacterial resistance indicate that polluted marine recreational waters and sands are sources of resistant bacteria contributing thus, to the dissemination of bacterial resistance.

Faecal bacteria in Perna perna (Linnaeus, 1758) (Mollusca: Bivalvia) for biomonitoring coastal waters and seafood quality

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identificação e avaliação de rizobactérias isoladas de raízes de milho

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Growth and antimicrobial activity of lactic acid bacteria from rumen fluid according to energy or nitrogen source

Objetivou-se avaliar os efeitos da suplementação com diferentes fontes de energia e de compostos nitrogenados sobre o crescimento e produção de bacteriocinas de bactérias ácido-láticas in vitro. As incubações foram conduzidas utilizando-se fluido ruminal originado de um novilho Holandês-Zebu fistulado no rúmen. O animal foi mantido em pastagem de Brachiaria decumbens recebendo 200 g/dia de proteína bruta suplementar. Os substratos e o inóculo foram acondicionados em frascos de vidro considerando-se oito tratamentos: celulose, celulose e caseína, celulose e peptona de soja, celulose e ureia, amido, amido e caseína, amido e peptona de soja e amido e ureia. Incubações sucessivas foram conduzidas para seleção dos microrganismos em função das fontes energéticas e de compostos nitrogenados. O amido favoreceu o crescimento de bactérias ácido-láticas em comparação à celulose. A suplementação com proteína verdadeira (peptona de soja e caseína) estimulou o crescimento dessas bactérias em comparação ao controle (sem suplementação com compostos nitrogenados). A adição de ureia não estimulou o crescimento de bactérias ácido-láticas. Nenhuma atividade antimicrobiana foi detectada a partir das colônias de bactérias ácido-láticas isoladas. Fontes de proteína verdadeira incrementam a competição entre bactérias fermentadoras de carboidratos estruturais e não-estruturais.

Susceptibility of Saccharomyces cerevisiae and lactic acid bacteria from the alcohol industry to several antimicrobial compounds

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of probiotic bacteria, isoflavones and simvastatin on lipid profile and atherosclerosis in cholesterol-fed rabbits: a randomized double-blind study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bottled mineral water as a potential source of antibiotic resistant bacteria

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparative genomics analyses of citrus-associated bacteria

Xylella fastidiosa 9a5c (XF-9a5c) and Xanthomonas axonopodis pv. citri (XAC) are bacteria that infect citrus plants. Sequencing of the genomes of these strains is complete and comparative analyses are now under way with the genomes of other bacteria of the same genera. In this review, we present an overview of this comparative genomic work. We also present a detailed genomic comparison between XF-9a5a and XAC. Based on this analysis, genes and operons were identified that might be relevant for adaptation to citrus. XAC has two copies of a type II secretion system, a large number of cell wall-degrading enzymes and sugar transporters, a complete energy metabolism, a whole set of avirulence genes associated with a type III secretion system, and a complete flagellar and chemotatic system. By contrast, XF-9a5c possesses more genes involved with type IV pili biosynthesis than does XAC, contains genes encoding for production of colicins, and has 4 copies of Type I restriction/modification system while XAC has only one.